Piston 1 in the figure has a diameter of 1.87 cm. Piston 2 has a diameter of 9.46 cm.
In the absence of friction, determine the force F, necessary to support an object with a mass of 991 kg placed on piston 2. (Neglect the height difference between the bottom of the two pistons, and assume that the pistons are massless).

Answer:

Answer is explained in the explanation section below.

Explanation:

Part A)

From conserve moment of force, we have:

F1d1 = F2d2

F1 x (3.80 x [tex]10^{-2}[/tex] m) = 15N x (15 x [tex]10^{-2}[/tex] m)

F1 = [tex]\frac{15 . 15 . 10^{-2} }{3.80 . 10^{-2} }[/tex]

F1 = 59.2 N

Force exerted by the biceps when the hand is empty.

Part B)

The 80 N weight acts at 33 cm and 15 N at 15 cm, then the center of mass is:

x = [tex]\frac{m1x1 + m2x2}{m1+m2}[/tex]

x = [tex]\frac{\frac{80}{9.8} (33 .10^{-2}) + \frac{15}{9.8}(15.10^{-2} }{\frac{80}{9.8} + \frac{15}{9.8} }[/tex]

x = 30.16 x [tex]10^{-2}[/tex] m

Total Weight is:

F = 80N + 15N = 95N

From the conserve moment of force, we have:

F ( 3.8 x [tex]10^{-2}[/tex] ) = 95N (30.16 x [tex]10^{-2}[/tex])

F = 754 N

Part C:

From the above two examples solved, the force exerted by the biceps is higher than downward force, due to this muscle need to be very strong.

Part D)

The force exerted by elbow on the forearm is:

The force exerted by the elbow and biceps are in upward direction and total weight is in downward direction. So, the balancing force in vertical direction is:

F2 + 754N = 95N

F2 = 95N -754N

F2 = -659N

Negative sign shows the force is in downward direction.

Part E)

The bicep muscle acts perpendicular to the forearm, so it is lever arm stays the same. but those of the other two forces decreases as the arm is raised. There tension in the biceps muscle decreases.

Part F)

Angle = 53 degrees.

So,

Force = FcosФ

Force = 754 cos 53

Force = 453.76 N

Part G)

The value of force has gone downwards. It has decreased from that of part B.

Answer:

L = 8.35 m

Explanation:

The lenght of a wire L can be calculated using the following expression:

L = R A/ρ  (1)

Where:

R: resistance of the wire

A: Cross section area of the wire

ρ: resistivity of the copper wire.

With this expression we realize that we do not have the area of the cross section, and the resistance of the wire either.

To calculate the area we can use the following expression:

A = πr²    (2)

If the diameter is 0.25 mm, then the radius is half, 0.125 mm. Converting this in meter it will have to be:

0.125 /1000 = 0.000125 m

Replacing we have:

A = π(0.000125)²

A = 4.91x10⁻⁸ m²

The reported resistivity of a copper wire is 1.68x10⁻⁸ Ω.m, so we just need to determine the resistance, which can be found using Ohm's law:

R = V/I  (3)

Replacing (3) into (1) we have:

L = (V * A) / (I * ρ) (4)

So finally, the length of the copper wire will be:

L = (12 * 4.91x10⁻⁸) / (4.2 * 1.68x10⁻⁸)

Hope this helps

Answer:Enegry

Explanation:Energy transfer is used to do work

Answer:

The work and energy is inter- related because if we are energetic then only we are able to work.

People who are weak and not energetic cannot work continuously.

Explanation:

hope this helps you....

Answer:

the distance between the stop signs is 120.7 m.

Explanation:

The car moved in three stages;

(1) It accelerates from rest at 2.0 m/s² for 6.2 seconds

(2) it moved at a constant speed for 2.5 s

(3) it finally decelerate at the rate of 1.5m/s²

(1) The distance moved by the car during the first stage;

s₁ = ut + ¹/₂at²

s₁ = 0 + ¹/₂ (2)(6.2)²

s₁ = 38.44 m

(2) The distance moved by the car during the second stage;

calculate the constant speed of the car,

v = u + at

v = 0 + 2 x 6.2

v = 12.4 m/s

The distance moved by the  car as it coasts for 2.5s: s₂ = vt

s₂ = 12.4 x 2.5

s₂ = 31 m

(3) The distance moved by the car during the third stage;

When the car stops, the final velocity is zero.

v² = u² + 2as₃

a = -1.5 m/s², since the car slowed down or decelerated.

0 = 12.4² + (2 x - 1.5)s₃

0 = 153.76 - 3s₃

3s₃ = 153.76

s₃ = 153.76 / 3

s₃ = 51.253 m

The total distance moved by the car from the start to stop = s₁ + s₂ + s₃

d = 38.44 m + 31 m + 51.253 m

d = 120.7 m

Therefore, the distance between the stop signs is 120.7 m.

Answer:

Please find attached pdf

Explanation:

Answer:

20 Hz

15.8 times

Explanation:

A

Although the range of frequency for any human's ear is usually said to be between 20 Hz and 20 kHz. And since the question asked for the least intense frequency, that has to be 20 Hz. Essentially the frequency most people perceive the least intense sound is 20 Hz.

B

A 100-Hz sound must be 10^1.2 times or 15.8 times more intense compared to a 1000-Hz sound to be perceived as equal to 60 phons of loudness

An action which would help in preventing and coping with heat-related conditions is: A. Drinking water.

Heat can be defined as a form of energy that is transferred from a physical object (body) to another, as a result of a difference in temperature. Also, heat is a condition of weather that is generally characterized by a high degree of temperature.

This ultimately implies that, heat is most likely to cause dehydration and high body temperature.

In order to prevent and cope with heat-related conditions, you should ensure that you drink water at regular intervals for hydration.

Read more on heat here: brainly.com/question/12072129

Answer: Approximately 11.76 joules per second

=========================================================

Work Shown:

Mass = 40 kg

Force pulling down = (mass)*(gravity) = 40*9.8 = 392 newtons

Roughly 392 newtons of force are pulling down on her.  

To climb the steps, she must apply 392 newtons of force upward.  

---------------

Displacement = 20*(15 mm) = 300 mm = 0.3 m

Work = Force*Displacement

Work = 392*0.3

Work = 117.6 joules of energy

---------------

Power = (Work)/(Time)

Power = (117.6 joules)/(10 seconds)

Power = (117.6/10) joules per second

Power = 11.76 joules per second, which is approximate

Answer:

The semiconductor rod will conduct electricity

Explanation:

Glass rod does not conduct electricity. Glass is one of the best insulators of electricity. But when a glass rod is replace with a semi conductor, then the semi conductor rod starts conducting electricity as the electrons are free to move.

Semi conductors are special materials in which the energy band lies in between the conductor and the non conductor. The conductivity of a semi conductor increases with the increasing temperature.

In an semi conductor the electrons are free to move and as they starts moving they conduct electricity. Thus a semi conductor rod replacing a glass rod conducts electricity.

Answer:

      I =  [tex]\frac{1}{4\pi \ r^2}[/tex]

we see the intensity decreases with the inverse of the distance squared

Explanation:

Intensity is defined as power per unit area,

           I = P / A

in this case we have that the sound is emitted in a spherical form therefore the area is

           A = 4 pi r2

therefore the intensity is

          I =  [tex]\frac{1}{4\pi \ r^2}[/tex]

as we see the intensity decreases with the inverse of the distance squared

Answer:

d

Explanation:

the US West Coast region probably has cooler summers than it would without the effect of a nearby ocean current.

ocean current can be defined as the horizontal movement of seawater which is produced by gravity, wind, and water density, it play an major role in the determination of climates of coastal regions.

The movement of ocean water is continuous which can be up three types such as Waves, Tides, Currents

The streams of water which flow continuously on the ocean surface in specific directions are called ocean currents, it affect the temperature of ocean water as Warm ocean currents increase the temperature whereas Cold ocean currents decrease the temperature.

The magnitude of the ocean currents is about  few centimeters per second to as much as 4 metres per second and the intensity of the ocean currents generally decreases with increasing depth.

There are two types of ocean currents such as Warm Ocean Currents

and Cold Ocean Currents

For more details ocean current,  visit

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Answer:

making cars that get better gas mileage

Answer: Making cars that get better gas

Explanation: Gradpoint

Answer:

0.8cm

Explanation:

Volume = mass/density = 160/8 = 20cm³

Volume = πr²h

r² = v/πh = 20/10π =0.64

r = √0.64 = 0.8

Answer:

[tex]\mathbf{ current(I) =1766.67 \ A}[/tex]

Explanation:

Given that:

The air resistance and friction = 700 N

The gravity caused force = 716 × 9.8 = 7016.8

Total force = (7016.8 + 700) N

Total force = 7716.8 N

∴

[tex]13 \times current(I) \times 0.84 = \dfrac{7716.8 \times 300}{2 \times 60}[/tex]

[tex]current(I) \times 10.92= 19292[/tex]

[tex]current(I) = \dfrac{19292}{10.92}[/tex]

[tex]\mathbf{ current(I) =1766.67 \ A}[/tex]

Answer:

law in acting

Explanation:

Answer:

b

Explanation:

this because if force (f) are resultant cos then the point is proportional to the direction of c at greatest possible forces

Solution :

Given that :

The energy of the protons, K.E. = 1.10 keV

                                                    [tex]$= 1.10 \times 10^3 \ eV $[/tex]

The current produced by the generator is I = 5 mA

                                                                        [tex]$= 5 \times 10^{-3} \ A$[/tex]

Now [tex]$1 \ eV = 1.6 \times 10^{-19 }\ J$[/tex]

Mass of the proton, m = [tex]$1.67 \times 10^_{-27} $[/tex] kg

Charge of the proton, [tex]$q_p = 1.6 \times 10^{-19} \ C$[/tex]

a). Therefore using the formula for K.E. we can find out the velocity of the proton.

[tex]$K.E. =\frac{1}{2}mv^2$[/tex]

[tex]$v=\sqrt{\frac{2K.E.}{m}}$[/tex]

[tex]$v=\sqrt{\frac{2\times 10^3 \times 1.6 \times 10^{-19}}{1.67 \times 10^{-27}}}$[/tex]

  [tex]$= 4.38 \times 10^5 \ m/s$[/tex]

b). We know that the current is :

 [tex]$I=\frac{\Delta Q}{\Delta t}$[/tex]

Therefore, the total charge in one second is given by :

[tex]$\Delta Q = I \times \Delta t$[/tex]

     [tex]$= 5 \times 10^{-3} \times 1$[/tex]

    [tex]$= 5 \times 10^{-3}\ C$[/tex]

So, the number of protons in this charge is given by :

[tex]$n = \frac{\Delta Q}{q_p}$[/tex]

  [tex]$=\frac{5 \times 10^{-3} }{1.6 \times 10^{-19}}$[/tex]

  [tex]$= 3.13 \times 10^{16}$[/tex] protons

Answer:

1.8 Kg 17.6N

Explanation:

I don't know the explanation hahaha

Answer:

The gravitational force on an object increases as the object’s mass increases.

Explanation:

This is the answer on Edmentum. :)

Answer:

These planets rotate around the sun in a circular path. Likewise in a heliocentric model it is believed that the sun is at the center of the universe and the planet earth along with all other planet move around it. Thus in both geocentric model and heliocentric model bodies in space move in circular orbits.

Answer:

The bodies in space move in circular orbits

Explanation:

I got it right on my test

Answer:

Explanation:

From the information given:

The diameter of the cylindrical heater (d) = 1 cm

The length of the cylindrical heater (l) = 0.25 m

The ambient air temperature [tex](T_{\infty})[/tex] = 25° C= (273+25)K = 298 K

The convective heat transfer coefficient (h) = 25 W/m² °C

The electric input Q = 5W

As stated in the question that if radiation is being neglected:-

Let also assume that;

the heat transfer takes place at a steady-state

1-D flow takes place

No external heat generation; &

No force convection takes place;

Then; the heat transfer through the convection can be calculated as:

[tex]Q = hA(T - T_{\infty})[/tex]

[tex]5= 25 \times (\pi \times (1\times 10^{-2}) \times 0.25) (T -0.25)[/tex]

By solving the above calculation:

T ( surface temperature of the heater) = 50.46° C  122.83° F

Answer:

6

Explanation:

nothingnsbejejjdbsbzbawkje

Answer:

Well the answer is 111 (rounded) km/h

Explanation:

788/7.1 is 110.9... so if you round it it would equal 111.

Answer:

The tree is 143.325 meters tall

Explanation:

The given parameters of the eucalyptus tree are;

The mass of the eucalyptus tree nut = 1.7 ounces

The speed of the nut at 50.3 m above the ground, v = 42.7 m/s

The equation for free fall is given as follows;

v² = 2·g·h

Where;

v = The velocity after falling through a height, h

g = The acceleration due to gravity = 9.8 m/s²

h = The height through which the seed has already fallen

Therefore, we have;

h = v²/(2·g) = (42.7 m/s)²/(2 × 9.8 m/s²) = 93.025 m

The height through which the seed has already fallen, h = 93.025 m

The height of the tree = h + The height of the seed above ground at the moment it was falling at 42.7 m/s

The height of the tree = 93.025 m + 50.3 m = 143.325 m

The height of the tree = 143.325 m.

The height of the eucalyptus tree is approximately 111.9 meters.

To determine the height of the tree, we can use the equations of motion. The initial velocity of the nut, u, is 0 m/s (since it is dropped), the acceleration due to gravity, a, is approximately 9.8 m/s², and the final velocity, v, is 42.7 m/s. We need to find the height, h. Using the equation v² = u² + 2a(h - u), we can rearrange it to solve for h: h = (v² - u²) / (2a) Plugging in the values, we get: h = (42.7² - 0²) / (2 * 9.8) = 111.9 meters Therefore, the height of the eucalyptus tree is approximately 111.9 meters.

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Answer:

There are 13 a

Explanation:

That's the answer how many a r there

Answer:

the convex mirror will produce image 3. the image is virtual and is now behind the mirror and it becomes smaller but remains upright.

Explanation:

Answer:

because the strength of Earth's gravitational field is not uniform everywhere, a given pendulum swings faster, and thus has a shorter period, at low altitudes and at Earth's poles than it does at high altitudes and at the Equator.

Answer:

A- Astronomical body

C- Galaxy

D- Comet

B- Moon

Hope this helps you! Have a great day!

Answer:

1. A

2. C

3. D

4. B

Explanation:

Answer:

B

Explanation:

Answer:

326,000

Explanation:

One acre-foot equals about 326,000 gallons, or enough water to cover an acre of land, about the size of a football field, one foot deep. An average California household uses between one-half and one acre-foot of water per year for indoor and outdoor use.